Float chamber construction



May 12, 1964 STERNER 3,132,684

FLOAT CHAMBER CONSTRUCTION Filed May 1, 1961 I l RESERVOIR INVENTOR. MELVIN F. STERNER Y wjM W Z TORNEYS United States Patent 3,132,684 FLOAT CHAMBER CONSTRUCTION -Melvin F. Sterner, Bloomfield Hills, Mich., assignor to p This invention relates to internal combustion engines, and more particularly to internal combustion engine fuel systems having a carburetion fuel inlet valve and float assembly for purposes of maintaining a predetermined fuel level in the fuel reservoir.

In the past, a mjor problem in fuel systems such as carburetors was flooding. This resulted generally in poor performance and poor fuel economy caused by the fuel pressure forcing the fuel inlet valve open. Thus,-ex cessive fuel entered the float chamber so that the fuel level in the metering system exceeded the desired level,

Many attempts have been made to overcome the flooding problem, but none have been completely successful during all operating conditions. Some of the methods involved the use of overflows, drains or valving arrange ments. The present invention provides means for controlling the level of fuel in the carburetor float chamber regardless of the fuel pump delivery pressure.

It is an object of the present invention to provide an improved carburetion fuel inlet valve and float assembly for maintaining a predetermined fuel level in the fuel bowl regardless of the fuel pump delivery pressure.

Another object of the present invention is to provide an improved combination carburetion fuel inlet valve and float assembly which is readily adjustable so as to change the requisite fuel level in the fuel bowl.

Still another object of the present invention is to provide a combination carburetion fuel inlet valve and float assembly which is simple in construction, economical to produce and efficient in operation.

A further object of the present invention is to provide a fuel bowl having an annular boss portion projecting from a wall of the fuel bowl, a valve seat in the boss portion, a carburetion fuel inlet valve and float assembly, the float of said assembly having an annular portion surrounding said boss portion and carrying a valve which is movable toward and away from said valve seat in response to changes of the fuel level in the fuel bowl.

fuel supply conduit 30 with the fuel chamber 12. t The float 22 has an annular portion 35 which surrounds the boss 28. Movement of the float 22 in response to'changes of the fuel level in the bowl 12 results'in the movement ofthe valve 24 towards and away from the valve seat 26.

The other end of the supply conduit 30 is connected to the outlet 34 of the fuel pump l6. Fuel pump 16 is of the mechanical type although it should be understood that other mechanical or electrical type fuel pumps may be used. The fuel pump 16 includes .a diaphragm 36, a pull rod 37, an inlet passage 38 having a check valve 40 therein, a diaphragm spring 41, a fuel chamber 39, and an actuating arm 42 which is operated by a cam 44 driven by-the cam shaft of the engine, not shown. It should also be understood that various means may be used to drive the fuel-pumps, depending on the type Other objects and features of the invention will be- 7 come apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating preferred embodiments of the invention, wherein the drawing is an elevational view in partial cross section illustrating a fuel pump supplying a carburetor embodying the invention.

Referring to the drawing, a fuel system is illustrated which includes a carburetor 10, formed to provide a fuel chamber or bowl 12, a fuel pump 16, and a fuel tank or reservoir 18. The fuel chamber 12 has a novel float and valve assembly 14 therein. The. carburetor 10 is mounted on the intake manifold 20 which is secured to an internal combustion engine, not shown. 7

The novel float and valve assembly 14 includes a float 22, an adjustable valve 24, a seat 26 which is threaded 32 is provided with an inwardly spherically curved flange which engages the flange 29. Nut 32 clamps the flange 29 of the float 22 and adjustable bearing 27 together. The

which has a passage 33 therein connecting one end of the boss 28 of the fuel chamber 12 contains the valve seat 26 of installation. Pump 16 is a common type diaphragm fuel pump, except that the usual outlet check valve has been removed. The pump inlet passage 38 is connected to the fuel tank 18 by conduit 46.

The operation of the invention is as follows. When the fuel chamber 12 is empty or the fuel level therein is low enough so that the valve 24 engages the valve seat 26, the engine is started and the actuating arm 42 is moved so as to operate the linkage connected to diaphragm pull rod 37. As a result, the diaphragm 36 is moved on its suction stroke against the spring 41. As a result, pressure is reduced in the fuel chamber 39 located below the diaphragm 36. This causes the normal atmospheric pressure to push the fuel out of the fuel tank, across the open inlet check valve 40, and into the chamber 39. When the cam shaft eccentric has revolved onehalf turn, the diaphragm spring 41 exerts pressure on the diaphragm 36. The check valve 40 is initially closed and fuel is then forced under pressure from the chamber 39 through the supply conduit 30, across the valve 24 into the chamber 12.

Fuel will continue to be supplied to thechamber 12 in the manner just described as long as the valve 24 can be seated due to a fuel level in the chamber 12 below the requisite level. When the predetermined fuel level has been reached or exceeded, the valve 24 can no longer be seated against its seat 26. During the next suction stroke of the fuel pump 16, the fuel in the conduit 30 is drawn back into the fuel chamber 39.. In addition, excess fuel from chamber 12 is merely sucked past valve 24, into conduit 30 and into chamber 39. When the predetermined fuel level has been reached, the spring loaded check valve 40 will not open since valve 24 is open.

The carburetor valve and float assembly 14 controls or maintains a predetermined fuel level in the fuel chamber 12 during all conditions of engine operation. Also, the fuel level can be adjusted by raising or lowering the adjustable valve 24 by manipulating the nut 32. In addition the spherical shape of the adjustable bearing 27, flange 29 and the flange on the nut 32 is extremely important since the spherical shape permits the control valve 24 to be angularly adjustedupon inclination of the fuel bowl. Thus the valve 24 is angularly andvertically adjustable.

The drawings and the foregoing specification constitute a description of the improved float chamber construction in such full, clear, concise and exact terms as to enable any person skilled in the art to practice'the invention, the scope of which is indicated by the appended claim.

What I claim as my invention is:

A carburetion system for an internal combustion engine comprising a carburetor, a fuel bowl for said carburetor having a predetermined fuel level, a tubular boss in said bowl extending upwardly from the bottom wall I inlet and return port in said bowl, a float with a centrally located opening therein in said bowl surrounding said boss, a plate attached to the top of said float and spanning said opening, said plate including a relatively small centrally located opening aligned with the opening in said float and which is surroundedby an inwardly curved flange forming a spherically shaped socket, a common inlet and return control valve for said common port, said control valve including a threaded sternhaving a spherically shaped bearing threaded thereon which is received in said socket to engage the inner surface of said flange, said stern including an extension extending upwardly through the opening in said plate beyond the top surface thereof, a nut threaded on the extension of said stem and including an outwardly spherically curved flange which engages the outer surface of said first-mentioned'fl'ange on said plate, said boss constituting a guide for preventing excessive lateral displacement of said float when said control valve is open, a fuel supply reservoir, a fuel pump,

said pump having a pumping chamber with an inlet port and an outlet port, pasage means connecting the inlet port of said pumping chamber to said supply reservoir, and

a fuel delivery conduit between the outlet port of said pumping chamber and said common inlet and return port in said bowl, said control valve being vertically adjustable relative to said float by adjustment of said nut and bearing on said threaded stem, and being angularly movable relative thereto as a result of the spherical shape of said bearing and said flanges.

References Cited in the file of this patent UNITED STATES PATENTS 669,611 Anderson et al Mar. 12, 1901 909,075 Fosnot Jan. 5,1909 1,415,162 Edwards May 9, 1922 1,635,175 Corwin July 12, 1927 1,768,487 Remington June 24, 1930 2,254,850 Mallory Sept, 2, 1941 FOREIGN PATENTS 6,258 France Dec. 12, 1850 369,455 Germany Feb. 19, 1923 

